Table of contentsResultsSponge-associated bacteria with anti-Vibrio spp propertiesHemolytic reaction of potential bacteriaResultsIsolation of sponge-associated bacteria from 3 different sponges yielded 80 morphologically different bacterial isolates. Nine bacterial isolates were obtained from the sponge Hyrtios sp., 20 bacteria isolated from Smenospongia sp. and 51 bacteria isolated from Verungola sp. Say no to plagiarism. Get a tailor-made essay on “Why violent video games should not be banned”?Get the original essaySponge-associated bacteria with anti-Vibrio spp properties.Twelve (15%) of 80 bacterial isolates were able to inhibit Vibrio growth indicated by a clear zone formation around the bacterial colony (Table 1). One bacterial strain (P2.24) could inhibit three Vibrio species, including V. harveyi, V. parahaemolyticus and V. vulnificus. Additionally, 10 bacterial strains specifically inhibit only V. harveyi, and 1 strain (P3.310) could inhibit both V. harveyi and V. parahaemolyticus. Twelve bacterial isolates showed varied clear zone diameter, ranging from 0.1 mm to 5 mm. The best anti-Vibrio spp. activity demonstrated by strain P2.24 due to its ability to inhibit three Vibrio species with different clear zone diameter. To confirm its anti-Vibrio spp. Activity, concentrated culture, supernatants and metabolite extracts of strain P2.24 were tested in an antagonism assay. Hemolytic reaction of potential bacteria Twelve potential strains producing anti-Vibrio spp. the compounds were hemolytically negative. They cannot lyse blood cells, as indicated by the absence of a clear zone formed around the colony after 24 hours of incubation. Three (P2.24, P3.310, D4.13) out of 4 potential strains (based on their ability to inhibit Vibrio spp. growth in a broad spectrum) were identified as having both NRPS and PKS genes, and one strain (P2.211) lacks both genes, as shown in Table 2. Adenilase (A) domain of NRPS and ketosynthase (KS) domain of The PKS gene of these bacteria was amplified by PCR method, resulting respectively into a DNA fragment of ± 1,000 bp and ± 700 bp (Fig. 1). Alignment using BlastN showed that all NRPS and PKS genes were similar to NRPS and PKS genes of Bacillus spp in various strains. Additionally, amplification of the 16S rRNA gene from four strains resulted in a fragment of ±1,300 bp. All three strains were highly homologous to Bacillus spp (Table 2). The genetic relationship for the NRPS-PKS gene of the potential strains was compared with their relative gene in the GenBank NCBI database and some references by constructing the phylogenetic tree. The phylogenetic tree of A domain of NRPS gene and KS domain of PKS gene was shown in Figures 2 and 3, respectively. The 16S rRNA-based evolutionary relationship of the potential strains with their closely related strains was carried out in Figure 4. Antibacterial activity of the culture, supernatant and extract of strain P2.24. Keep in mind: this is just a sample. Get a custom paper now from our expert writers.Get a custom testThe bacterial culture used in this test contains approximately 7.8 x 107 cells/mL of medium or 1.6 x 107 cells/20 µL. The culture, the supernatant as well as the extract of the P2.24 strain systematically presented anti-Vibrio spp. activities as indicated by the formation of a light area around the paper disk (Fig.5). The most powerful inhibitory effect was demonstrated by the concentrated culture of strain P2.24 against V. parahaemolyticus. A clear zone was also shown by ampicillin as.